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Scala example source code file (ByteArrayReader.scala)

This example Scala source code file (ByteArrayReader.scala) is included in my "Source Code Warehouse" project. The intent of this project is to help you more easily find Scala source code examples by using tags.

All credit for the original source code belongs to scala-lang.org; I'm just trying to make examples easier to find. (For my Scala work, see my Scala examples and tutorials.)

Scala tags/keywords

array, byte, bytearrayreader, char, double, float, int, long, string

The ByteArrayReader.scala Scala example source code

/*     ___ ____ ___   __   ___   ___
**    / _// __// _ | / /  / _ | / _ \    Scala classfile decoder
**  __\ \/ /__/ __ |/ /__/ __ |/ ___/    (c) 2003-2013, LAMP/EPFL
** /____/\___/_/ |_/____/_/ |_/_/        http://scala-lang.org/
**
*/


package scala
package tools.scalap


class ByteArrayReader(content: Array[Byte]) {

  /** the buffer containing the file
   */
  val buf: Array[Byte] = content

  /** the current input pointer
   */
  var bp: Int = 0

  /** return byte at offset 'pos'
   */
  def byteAt(pos: Int): Byte = buf(pos)

  /** read a byte
   */
  def nextByte: Byte = {
    bp += 1
    buf(bp - 1)
  }

  /** read some bytes
   */
  def nextBytes(len: Int): Array[Byte] = {
    val res = new Array[Byte](len)
    System.arraycopy(buf, bp, res, 0, len)
    bp += len
    res
  }

  /** read a character
   */
  def nextChar: Char = {
    bp += 2
    getChar(bp - 2)
  }

  /** read an integer
   */
  def nextInt: Int = {
    bp += 4
    getInt(bp - 4)
  }

  /** read a long
   */
  def nextLong: Long = {
    bp += 8
    getLong(bp - 8)
  }

  /** read a float
   */
  def nextFloat: Float = java.lang.Float.intBitsToFloat(nextInt)

  /** read a double
   */
  def nextDouble: Double = java.lang.Double.longBitsToDouble(nextLong)

  /** read an UTF8 encoded string
   */
  def nextUTF8(len: Int): String = {
    val cs = scala.io.Codec.fromUTF8(buf, bp, len)
    bp += len
    new String(cs)
  }

  /** extract a character at position bp from buf
   */
  def getChar(bp: Int): Char =
    (((buf(bp) & 0xff) << 8) + (buf(bp + 1) & 0xff)).asInstanceOf[Char]

  /** extract an integer at position bp from buf
   */
  def getInt(bp: Int): Int =
    ((buf(bp  ) & 0xff) << 24) +
    ((buf(bp + 1) & 0xff) << 16) +
    ((buf(bp + 2) & 0xff) << 8) +
     (buf(bp + 3) & 0xff)

  /** extract a long integer at position bp from buf
   */
  def getLong(bp: Int): Long =
    (getInt(bp).toLong << 32) + (getInt(bp + 4).toLong & 0xffffffffL)

  /** extract a float at position bp from buf
   */
  def getFloat(bp: Int): Float = java.lang.Float.intBitsToFloat(getInt(bp))

  /** extract a double at position bp from buf
   */
  def getDouble(bp: Int): Double = java.lang.Double.longBitsToDouble(getLong(bp))

   /** skip next 'n' bytes
  */
  def skip(n: Int) {
    bp += n
  }

}

Other Scala source code examples

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